Investigating the effects of vibration-assisted process on void reduction behavior for carbon-quartz hybrid composite joint

Carbon-quartz hybrid composite joint emerged as a key strategy to achieve high performance while keeping special functions has given rise to a need for high-quality manufacturing to avoid void defects with low curing pressure. The vibration-assisted process is an efficient method for processing composite components under vacuum pressure, but the reduction mechanism of void caused by vibration excitation is not completely understood. Herein, a dynamic model coupling gas bubble dynamics with the power-law fluid constitutive model is established to investigate void radial oscillation, and multi-dimensional bifurcation diagrams are employed to analyze influences of vibration and material parameters on void collapse. Meanwhile, the combination of processing experiments, performance tests and microscopic characterizations is used to clear real effects of applying vibration on void reduction within joints. The results demonstrate that when the vibration pressure coefficient falls within [1 1.5] and the frequency lies within [10 2000] Hz, most voids exhibit a tendency to collapse. When the resin viscosity remains below 1 Pa·s the viscous resistance opposing void collapse is substantially weakened. Moreover, compared with the 0.0 MPa autoclave process, the 10 g vibration-assisted vacuum process reduces the void content within the joint from 7.9% to 0.44% and increases the bending strength by 37.68%. Overall, this study is expected to enrich the understanding of void reduction under vibration excitation and demonstrates the potential of the vibration-assisted vacuum process for curing high-quality hybrid composite joints.